TR6 TR6 tick in first...

[TexasKnucklehead]

So I'm out for a TR6 drive in the wonderful weather. Minding my own business at a light and I hear "Smile". There is a blond in the car in the next lane with her passenger window down, pointing her camera at me. Is that a TR4?

After I run some errands, I find myself having to pull out very hard into traffic as someone is signaling to turn into the same parking lot. I pull out into 3 lanes of traffic, into the right lane, hard enough for both rear tires to sound an audible alert, but cut my acceleration short when I hear an unusual clicking, monotonically incrementing with engine speed. As I shift into second gear, the noise dissipates. At each subsequent red light, I gingerly pull out to hear the noise again, always disappearing as soon as I shift to second. The sound seems to be coming from the passenger rear hub.

At home I lift the rear end. Spin the wheel, check for play in the half shaft universals and look for a sloppy wheel. Nothing. I can lightly hear the noise when the car is in neutral, and much quieter if the clutch is pressed in. If I allow the car to drift backwards down the driveway in neutral there is no noise. If I pull back up in second gear, there is no noise. If I drift backwards in second gear with the clutch pressed in, there is no noise. If I drift backwards in first gear with the clutch in, it ticks loudly the whole way back. If I pull back forward in first gear, the noise is there. Reverse gear seems to be normal.

I overhauled this transmission a few years ago and checked the oil level early this spring. (There's still the usual drips of oil under there, so I know it's not empty.) I hate to pull the trans again, but I can't see another option.

Any idea what I've broken?

 

[martx-5]

...


Any idea what I've broken?

Sounds like it might be part #23 and/or #57 in this plate...

Bummer...

 

[John_Mc]

Whatever you broke, it was the blonde's fault.

 

[TR4nut]

Well that stinks - It does sound like something weird happened with 1st gear based on your testing. That and the blonde mistaking the car for a TR4!

 

[TexasKnucklehead]

So I got the transmission out -I'd nearly forgotten how many ways there are to balance a 1/2" wrench on one side of the firewall, while removing a nut from the other. Sometimes I should get help.

There appears to be 4 or 5 spots of something stuck on a few of the teeth of first gear. It appears to be grease and/or something. I didn't scrape it off (yet) or drop the counter shaft to get it apart farther. I didn't even drain the oil, but so far I'm not seeing anything serious.

I'm going to request a local expert have a look see (at the transmission).

 

[DougF]

When I broke a tooth in first gear, I could feel it through the shifter. There was a definite clunky chatter and a noisy vibtration of the shifter. As soon as I was out of first, the noise was gone.

Does the noise occur if you take it easy in 1st? Or does it only happen if you give it moderate to heavy pedal. Do you hear anything if you accelerate hard in second?

 

[startech47]

Look for something stuck in the root of the mating cluster gear. Maybe something floated up in the oil and became embedded in the tooth. Can you get a mirror in there to view the other gear and rotate the gears?

 

[Twosheds]

It sounds like a tooth broken from first gear (#57 in Art's plate).

I have experimented with this...

Only mine ticked in reverse, too.

 

[TexasKnucklehead]

I looked closer this morning. It's not grease stuck to the tooth, it's metal (as in part of the tooth that doesn't wipe off). I can't see the mate under it even with a mirror and flash light, but I'm assuming the worst.

Pulling out as hard as possible in 2nd has no tick. Pulling out in 1st as gently as possible makes the tick -even coasting in 1st gear with the clutch pressed in makes the noise. Reversing makes the usual gear meshing noise, but the tick would be much louder than that.

I have to take it apart more... maybe it's time for an overdrive.

 

[Moseso]

Sure sounds like a chipped tooth in the 1st gear set to me.
Reverse is a completely different gear set in the 4-syncro transmissions.

John and I have both experimented with the broken 1st gear tooth on the countershaft in the non-syncro TR3 transmission. It's easy to understand why that might happen in those -- a little more difficult to explain in the syncro 1st.

This is what mine looked like after removing everything to get at it. The mainshaft 1st gear was fine -- entirely reusable.

 

[cheseroo]

I had the same clunking/clicking problem and it was a broken tooth on #57 in Art's diagram. It's hard to see the countershaft gears from above but I'd look hard at it with a flashlight as you turn it. With the gearbox apart you can see the layshaft is an obvious weak link. The mainshaft turns in big ol bearings and the layshaft turns in small needle bearings. The gear action is trying to force the two shafts apart and the weakest link gives out first. With mine I'me guessing the needle bearings failed which allowed the layshaft to drop away from the mainshaft. Instead of a full gear mesh just the tips were in contact and the layshaft gear failed. You generate the most torque in the lower gears which is why they go first. As I recall, the first gear layshaft was kind of expensive but I was able to get one from a spare trans that was given to me. The VTR site has good instructions on how do a rebuild your own trans

 

[Silverghost]

Could that be the remains of a wayward needle bearing? Or damage caused by a wayward needle bearing?

 

[TexasKnucklehead]

Well, I'm only a few minutes with tool #S4221A-15A to know exactly whats wrong. Unfortunately, I have no such tool and pulling the center bearing without one is very difficult. I saw a tool at harbor freight that looked like a replacement for #S4221A-15A -or at least is used to pull a bearing from that little exposed ridge, but I can't run there until tomorrow. I should have got one last time I was there, but who knew I'd be pulling a TR6 transmission apart again?

The counter shaft has a little wear but not excessive. The PO had installed a threaded bolt into the clutch cross shaft in place of the tapered pin. It broke off when trying to remove it. But it didn't break where I can pull the fork off the shaft. The good news, is I happen to have a spare case with a cross shaft in it. -it's always something.

 

[TexasKnucklehead]

Yep. Broken tooth maketh funny thoundth.

As young Frankenstein would say, it could be worse.

 

[71MKIV]

at least it didn't get crunched into anything else

 

[TR3TR6]

Did the bearing puller from Harbor Freight work or did you have to use something else? If it did, could you tell me what the part # was for the puller? Thanks.

 

[TexasKnucklehead]

I used "Pittsburgh Bearing Puller/Seperator set" model 93980. -Actually only the larger of the set, but with 2) longer 1/2" x 8" bolts and 2) 3/8" bolts. A picture is probably in order, but I didn't take one. Perhaps I'll mock it up, but basically, the extractor was bolted snug against the transmission case with 4 small places fitted into the bearing recess (where that snap ring was) using the longer bolts. Then the two 3/8 bolts are threaded into the side of the separator, bottoming out at the transmission case -well almost bottoming out because the threaded holes are a bit larger than the case, but a washer placed between the case and separator allows the bolt something to press against. -A better approach would be to extend the extension screws with a foot or two of all-thread (3/8-16) so the yoke adapter could be used to press against the shaft instead of pressing against the case. It worked, but I had to keep 'shimming' the washers until I got the bearing off the shaft.

 

[hondo402000]

cool that you figured it out, sorry about the broken tooth, so is that part available?

Hondo

 

[TR3TR6]

Thanks for the info. I'm always looking for tools that will work on these British cars.

 

[TexasKnucklehead]

Hondo, the part is available new, but a club member had one at a much better price (free). While I was in there I changed:

1st/rev gear cluster/shaft (used)
All the syncros
counter shaft (harder)
counter shaft bearings (caged style)
2nd gear adjustment washer (to get clearance within spec)
shift collar springs
main shaft cir-clips
drilled and installed grade-8 thru-bolt in clutch cross shaft (removed broken non-hardened bolt that replaced the original pin)
used MT90 oil

After I finally figured out why my clutch refused to fully disengage (I only tightened one bolt on the slave triangle), I took it for a spin tonight with the top down. It's in the 40's here in Houston and that's cold for most of us. The transmission shifts like it's not a Triumph. -or at least better than new. All the gears work in any direction with a smooth, positive, noiseless feel. I'm so happy I could peel out -but instead, I'll try to remember what I was doing on the TR3 before this all started.

I also learned that heating/cooling is an easier way to install and remove bearings.